Blender Equivalent to Padding?
You can use Inset Faces. It doesn't do it exactly like in your image. Instead it looks like this.
  

Select the faces you want to inset and press I and drag the mouse. It works with  multiple faces as well.
  

And if you do II when you have multiple faces selected, it will inset them individually.
  

Instead of dragging the mouse, you can type the inset distance immediately after I or II.  

This doesn't pad the plane outwards, increasing its size, but rather insets within the current size. This can, of course, be remedied by scaling it up before insetting. Also, as you can see, the corners are handled differently.